Were there any Senate hearings involved in ending WW I trench warfare?

I know that tanks becoming more reliable was a part of why trench warfare started to dissipate at the end of World War I.

That premise isn't correct. Tanks were a part of why World War Two didn't devolve into trench warfare again (despite many expecting it to), but a WWI tank was rather different.

Tanks were an attempt to break the stalemate of WWI, but for the most part failed. WWI tanks were intended to trundle across No Man's Land, immune to rifle and machine gun fire, and overrun the trenches allowing infantry to follow up. They lacked the mobility and reliability to do this effectively, most tanks broke down or bogged down, often before even reaching the battlefield. This problem still plagues tanks today. Their slow speed, typically a walking pace, and difficult steering made them easy targets for a calm artillery gunner. And their poor "armor", not real armor, but soft boiler plate, could be penetrated by even improvised weapons like a reversed bullet.

David Fletcher, of the Bovington Tank Museum, has a Tank Chat about the British Mark I tank. While there were other tanks and improvements, his comments about the Mark I are generally applicable to WWI tanks. Another good resource is The Great War and their special on Tank Development In WWI.

More importantly they lacked the communications and tactics to coordinate with the infantry and artillery (aka "combined arms"). WWI tanks, if they crossed the trenches, had a tendency to continue on alone, reaching the enemy rear area and then sort of milling about. Being basically blind, it was fairly easy to roll up an artillery piece and blast it.

And there simply weren't enough of them, working and in position, at any time to have a strategic effect.

I want to know if there was much in the way of political commentary or public opinion concerning trench warfare.

I'm pretty sure nobody liked it, and everyone was finding a way to break the stalemate, but their total lack of experience with modern war meant that most of the ideas were utterly unrealistic. They probably made it worse by employing short sighted or impractical strategies. Everyone was looking for "the big push", some magic bullet to break the stalemate, rather than looking at the problem systemically.

Based on your comments it seems the premise is that trench warfare was some sort of choice...

I guess i'll look for newspaper and/or editorials on what public opinion might have been. I'm trying to write and find sources that will explain reasons behind ending trench warfare – robluke 9 mins ago

Nobody planned trench warfare. WWI in the west was supposed to be a highly mobile war like the proceeding Franco-Prussian War of 1870 was. The initial German attack went according to the Schlieffen Plan, a giant right hook by the German army aimed at Paris that nearly worked. It was only when the attack ran out of steam that the armies began digging defensive trenches. The Germans fell back along a ridge and everyone dug in.

And they kept on digging. They typical way of dealing with a strong defensive line is to charge it, now futile with machine guns and rapid fire rifles, or outflank it, to get around the sides. As each side tried to outflank each other, they extended their trenches further and further and further until they were literally racing each other north to the sea. The result was, very quickly, a contiguous line of defenses from the North Sea to Switzerland.

Both sides sought to break the stalemate with technology, and tactics, but mostly by opening up new fronts like attempting to capture Constantinople by sea. These all failed.

What finally broke the stalemate was new "Stormtrooper" tactics and training first used en masse in the 1918 German Spring Offensive, the Kaiserschlacht. Rather than trying to control large, unwieldy, overambicous attacks by hundreds of thousands of men, these centered around small, independent, heavily armed squads infiltrating the enemy positions and overwhelming them with speed, surprise, and heavy firepower. Submachine guns, grenades, pistols, and brutal hand weapons were the weapons of choice. The Allies had also improved their tactics. These basic tactics are still used today.

This nearly won the war for the Germans, but both sides were exhausted after years of taking millions of casualties. The Germans didn't have enough resources to follow up on their successes, and the Allied lines were being stiffened by fresh troops from the US.

Trench warfare ended, in large part, because the Allies won the war of attrition. The Germans no longer had the reserves to replace their casualties in the trenches, and they'd just used up their best troops in the Spring Offensive. Their tactical successes left them with longer lines to defend, and a million less men to defend them. While the Allies had fresh US troops to act as replacements. The German lines thinned and finally collapsed in a collection of battles known as The Hundred Days Offensive.